PubMed1991
The importance of the region in position 148-192 for the biological activities and receptor-binding capacity of the human IL-1 beta protein has been assessed by the use of mAbs. Four mAbs have been used, which recognize different epitopes within the 148-192 region. None of the mAbs could inhibit binding of IL-1 beta to IL-1RI (expressed on T cells and fibroblasts), suggesting that the 148-192 region does not contain IL-1RI binding sites. Conversely, mAbs Vhp20 (recognizing the fragment 166-169) and BRhD2 (directed to an epitope in the sequence 177-186) recognize sites partially involved in binding to IL-1RII (expressed on B cells, macrophages, and PMN). Only mAbs BRhD2 and FIB 1 (which recognizes an epitope in the sequence 174-186) can inhibit IL-1 beta-induced thymocyte proliferation, whereas all four can inhibit the adjuvant capacity of IL-1 beta in vivo. It is concluded that the region 148-192 encompasses domains important for T cell activation but not for binding to the IL-1RI on T cells, others involved in immunostimulation in vivo, and others important for binding to IL-1RII, although not directly involved in it.